More bulk than your average slim case, but if you need the extra protection this is the way to go.
If you have a Nexus 5 — in particular the white model — you know it can be a bit slick in the hand and relatively easy to drop. That's whether you're predisposed to dropping phones (whether we like to admit it) or not, and if you're not strictly against having a case, maybe putting a little extra protection on your device is a good idea.
Incipio offers its DualPro cases in a variety of styles and colors for different devices, but the DualPro hard-shell case is probably the most "standard" of the bunch. If you're not familiar with the DualPro design, it brings together a soft rubber case that offers full coverage with a harder shell that snaps around the edges and back for more rigidity and shock absorption.